The present invention relates to a flame retardant/heat resistant agent and adhesive and flame retardant/heat resistant cloth material, particularly to the application of a flame retardant/heat resistant adhesive to cloth material that may be used to support a polymeric material attached thereto.
There are several known methods for improving the flame retardance of cloth materials. One method is the inclusion of an inorganic silica containing compound within the fiber of the cloth to give increased heat and flame resistance to the cloth. Examples of such applications include fire blankets, which can have glass fiber incorporated within the weave of the fabric. The glass fabric gives strength to the cloth and helps to prevent flame penetration as it is nonflammable. However the glass fibers are heavy and can be difficult to work with. Of course, the use of asbestos, a naturally occurring fibrous silica compound, has been restricted due to its associated problems.
Alternatively, the flame resistance of most cloth materials can be enhanced by the impregnation of the material with a flame retarding agent. Agents used are generally high oxidation state salts or compounds of non-metal oxides, such as phosphates and sulphates. Although this method of improving the flame retardance of cloth is highly flexible, it does not necessarily improve the bonding of the cloth material to any plastic applied thereto.
Some other materials are naturally flame retardant, examples include some polyamides and aramids such as Kevlar. These materials have the disadvantage that they can be unsuitable for cloth material, particularly when providing a fiber that can be woven into cloth.
It is an object of the present invention to provide a flame retardant/heat resistant agent and adhesive, which can be applied to cloth material, rendering the cloth material flame retardant/heat resistant, and which improves the binding of the cloth material to a variety of thermoplastic polymers.
The present invention provides a flame retardant/heat resistant agent comprising antimony and phosphorus oxide compounds.
Optionally the flame retardant/heat resistant agent also includes one or more compounds selected from the group including silicates and melamine cyanurate.
Preferably the fabric material is rendered flame retardant/heat resistant by being sprayed with the flame retardant/heat resistant agent or being immersed in said agent.
The invention also provides a flame retardant/heat resistant adhesive comprising antimony and phosphorus oxide compounds.
Most preferably said antimony and phosphorus oxide compounds are antimony trioxide and/or pentoxide and the ammonium salt of polyphosphate.
Optionally said flame retardant/heat resistant agent is a mixture of melamine cyanurate, silicates and ammonium polyphosphate and antimony oxides.
Preferably also the fabric material, to which the adhesive can be applied is knitted.
Optionally the fabric material, to which the adhesive can be applied, is woven using the leno weave method.
Preferably also the fabric material is selected from the group consisting polyesters, Nylon 6/6, Nylon 12, polyamides, copolyerised polyamides and Rayon.
Preferably also the weight of the cloth when knitted/woven is between 125 and 670 grams per square meter.
In a preferred embodiment said fabric material is dipped in DMK/F12, a chlorinated acrylonitrile copolymer, mixed with a combination of antimony and phosphorus oxide compounds.
Preferably also the adhesive is applied as a coating to the fabric material at between 40-110 grams per square meter.
Preferably also the adhesive coating is based upon one of the group consisting of chlorinated acrylonitrile copolymers or PVC.
Optionally the adhesive coating may be based on melamine Cyanurate.
More preferably said adhesive also contains a mixture of phosphorus and antimony oxides as a flame retardant agent.
Most preferably said adhesive coating is a PVC adhesive, impregnated with a mixture of antimony phosphorus oxide compounds.
Preferably the thermoplastic polymer materials are selected from the group consisting of polypropylene, acrylonitrile-butadiene-styrene, thermoplastic olefins, polycarbonates, PVC, nylon 6/6 and copolymers, mixtures and/or halogenated analogues thereof.
In a preferred embodiment the flame retardant/heat resistant adhesive of the present invention is applied to cloth material which is used as a backing material to thermoplastic olefin based polymers. The combination of thermopolymer and backing material produced can be utilized as deployment doors for car airbags, particularly for car passenger airbags, where the cloth material ensures that the deployment of the airbag does not cause destruction of the airbag deployment door.
In a further embodiment the flame retardant/heat resistant adhesive is applied to cloth material which is used as a strengthening material in thermoplastic construction such as automobile bumpers and plastic pipes.
The preferred embodiment of the invention when applied to cloth material provides a very thermostable (240-260xc2x0 C.) flame retardant cloth material that has a high cohesion and adhesion to several plastics, including; polypropylene, ABS, thermoplastic olefins, polycarbonates, PVC and nylon 6/6. As a result of the leno weave construction the cloth material has a high tear strength due to the double warp. Also the leno weave gives the material a high crimp and high flexibility. The adhesive finish give the cloth material a finish that includes suitable stiffness for the extrusion process and good compound penetration as well as the heat resistant/flame retardant qualities.
The flame retardant/heat resistant adhesive of the present invention will now be further described with reference to the following examples.